The subject matter disclosed herein relates to methods of determining a size of a defect. Various components, for example turbine components used in power generation, require the ability to operate under high stress. Welds are potential sources of weakness in a component due to the potential number and size of defects present. One method of determining the size of defects includes directing sound beams focused to a small point towards the particular defect. Some methods for producing such sound beams include reducing the size of a transducer that produces the sound beam, using lenses to focus a sound beam, and using a two-dimensional phased array to focus the beam. These methods can be complex and costly. The present disclosure provides a method and apparatus for determining a size of a defect using an ultrasonic linear phased array.